NO.30 SCR SYSTEM NOISE [MZR-CD 2.2]SM2444566
NO.30 SCR SYSTEM NOISE [MZR-CD 2.2]

id0103f3843300

30

SCR SYSTEM NOISE
DESCRIPTION
• Excessive noise from SCR system component.
POSSIBLE CAUSE
• Reverting valve operation noise
• Urea injector operation noise
• Urea pump operation noise
• Swaying sound of AdBlue® in urea tank
• Reverting valve loosely installed
• Urea injector loosely installed
• Urea pump loosely installed
• Exhaust system loosely installed
• Noise from the vehicle system except the SCR system (i.e. solenoid operation sound etc.)

Diagnostic Procedure

STEP

INSPECTION

RESULTS

ACTION
1
Confirm the situation in that the noise is generated.
—
If the noise is generating when the switch the ignition ON:
Go to the next step.
If the noise is generating while idling:
Go to Step 3.
If the noise is generating while the driving:
Go to Step 7.
If the noise is generating after the switch the ignition off:
Go to Step 12.
2
Switch the ignition to ON.
Confirm the situation in that the noise is generated.
Is the clicking sound once from around the urea tank?
Yes
The system operation is normal.
(The reverting valve normal operating sound.)
If the reverting valve operation sound is bigger the other vehicle, inspect and repair the reverting valve installation.
No
The noise is generated by the other component of the SCR system.
The souse of noise is other system part (i.e. solenoid valve).
3
Start the engine and run it at idle.
Confirm the situation in that the noise is generated.
Is the noise from the urea injector?
Yes
Go to the next step.
No
Go to Step 5.
4
Compare the urea injector operating sound with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair for the urea injector and the exhaust system part.
No
The system operation is normal.
Note
• The urea injector operating sound frequency each the SCR system condition is following:
― Below 1.0 Hz: Under normal operating
― Approx. 3.3 Hz: Under diesel particulate filter regeneration or protection for high temperature at the urea injector
5
Confirm the situation in that the noise is generated.
Is the noise from the urea pump?
Yes
Go to the next step.
No
The noise is generated by the other component of the SCR system.
The souse of noise is other system part (i.e. solenoid valve).
6
Compare the urea pump operating sound with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair for the urea pump installation.
No
The system operation is normal.
7
Caution
• While performing this step, always operate the vehicle in a safe and lawful manner.
Drive the vehicle under the customer’s proposal condition.
Confirm the situation in that the noise is generated.
Is the noise from the urea injector?
Yes
Go to the next step.
No
Go to Step 9.
8
Compare the urea injector operating sound with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair for the urea injector and the exhaust system part.
No
The system operation is normal.
Note
• The urea injector operating sound frequency each the SCR system condition is following:
― Below 1.0 Hz: Under normal operating
― Approx. 3.3 Hz: Under diesel particulate filter regeneration or protection for high temperature at the urea injector
9
Confirm the situation in that the noise is generated.
Is the noise from the urea pump?
Yes
Go to the next step.
No
Go to Step 11.
10
Compare the urea pump operating sound with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair for the urea pump installation.
No
The system operation is normal.
(The urea pump operation sound.)
11
Confirm the situation in that the noise is generated.
Is the noise from the urea tank?
Yes
The noise is that swaying sound of the AdBlue® in urea tank.
No
The noise is generated by the other component of the SCR system.
The souse of noise is other system part (i.e. solenoid valve).
12
Switch the ignition to off.
Confirm the situation in that the noise is generated.
Is the clicking sound from urea injector?
Yes
Go to the next step.
(The sound is normal urea injector operating sound when returning AdBlue® to urea tank from the urea injector.)
No
Go to Step 14.
13
Compare the noise with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair for the urea injector and the exhaust system part.
No
The system operation is normal.
14
Confirm the situation in that the noise is generated.
Is the clicking sound once from around the urea tank?
Yes
Go to the next step.
(The sound is normal reverting valve normal operating sound when returning AdBlue® to urea tank from the urea injector.)
No
Go to Step 16.
15
Compare the noise with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair the reverting valve installation.
No
The system operation is normal.
16
Confirm the situation in that the noise is generated.
Is the motor operation sound from the urea pump?
Yes
Go to the next step,
(The sound is normal urea pump operating sound when returning AdBlue® to urea tank from the urea injector.)
No
The noise is generated by the other component of the SCR system.
The souse of noise is other system part (i.e. solenoid valve).
17
Compare the noise with other vehicle.
Is the operation sound of customer vehicle bigger than the other vehicle?
Yes
Inspect and repair the installation of the urea pump.
No
The system operation is normal.
18
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR-CD 2.2].)
• If the malfunction remains, inspect the related Service Information and perform repair or diagnosis.
― If the vehicle is repaired, troubleshooting completed.
― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available.